1. Synthesis of Ultra-high Molecular Weight SiO2-g-PMMA Particle Brushes.
- Author
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Wang, Zongyu, Liu, Tong, Lin, Kevin C., Li, Sipei, Yan, Jiajun, Olszewski, Mateusz, Sobieski, Julian, Pietrasik, Joanna, Bockstaller, Michael R., and Matyjaszewski, Krzysztof
- Subjects
MOLECULAR weights ,SILICA nanoparticles ,BROOMS & brushes ,NANOPARTICLES ,POLYSTYRENE ,DEGREE of polymerization - Abstract
A simple route to synthesize ultra-high molecular weight particle brushes by surface-initiated atom transfer radical polymerization (SI-ATRP) from silica nanoparticles was developed. SiO
2 -g-PMMA and SiO2 -g-PS particle brushes were prepared with different [SiO2 –Br]0 concentration of initiating sites on the surface of the nanoparticles. Ultra-high MW (> 106 ) SiO2 -g-PMMA particle brushes with narrow molecular weight distribution (< 1.3) and different grafting densities were synthesized. The grafting density of SiO2 -g-PMMA particle brushes decreased with increasing target degree of polymerization. The same conditions were applied to the synthesis of SiO2 -g-PS particle brushes. However, due to the lower propagation rate constant of styrene, coupling between SiO2 -g-PS particle brushes occurred and also some fraction of unattached homopolystyrene was generated by the thermal self-initiation of styrene, preventing successful synthesis of ultra-high MW SiO2 -g-PS particle brushes. [ABSTRACT FROM AUTHOR]- Published
- 2020
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